Who Determined That the Sun Was a Star and More Questions From Our Readers

You asked, we answered

Who determined that the sun was a star, like the stars in the nighttime sky?

Mike Curtiss
West Richland, Washington

No single astronomer had this realization. Prominent thinkers considered the possibility since classical antiquity; they had creative rhetorical argument on their side, but no proof. By the late 19th century, we knew what stars were, and we knew the distances from the earth to a few stars and to the sun; with that data, astronomers determined that these bodies released energy in roughly comparable amounts. Then spectroscopic examination revealed that the chemical elements in the solar atmosphere were just like those found in common yellow-colored stars spread across the sky.

David H. DeVorkin
senior curator, National Air and Space Museum

Did Norsemen explore the west coast of Mexico?

Dhani Schimizzi
Rochester, North Carolina

No; Vikings never got to the west coast of America. They probably didn’t travel much farther west or south than the Gulf of St. Lawrence.

William Fitzhugh
anthropologist, National Museum of Natural History

Who invented the hashtag?

Gary Miller
Davenport, Florida

San Francisco technologist Chris Messina is usually credited with being the first to use the hash sign (#) as a tag on Twitter as early as 2007. After Twitter formally adopted it, the tag became standard on other social networks. This phenomenon shows how online communities develop their own languages, which spread and then evolve or wither over time.

How can something like a tiny, harmless spider or a clown make your heart race and your palms sweat? And for the love of all things science, how can you make these fears stop? Find out in this one-minute video, where Ask Smithsonian host Eric Schulze delves deep into the dark recesses of our minds to get at the facts behind our phobias.

Do pumas and jaguars share habitats in Central or South America and compete for the same resources? Could the two species crossbreed?

James DeWitt
Lakewood, Colorado

These two big cats overlap in many places, from the U.S.-Mexico border south. And where they overlap, they compete for resources. Jaguars (the larger of the two) tend to take the larger prey, pumas the smaller prey. Crossbreeding of most cat species can produce hybrids, but I know of no well-documented cases involving pumas and jaguars.

Kristofer M. Helgen
curator of mammals, National Museum of Natural History

John Adams is often quoted as saying the colonists were divided by the American Revolution: one third for, one third against and one third on the fence. Is that correct?Tom Hansen
Rolling Meadows, Illinois

Roughly speaking, yes. It’s difficult to be demographically precise about these things, but Adams was a shrewd judge of the political landscape. His assessment shows that the Revolution was by no means guaranteed to succeed. Most interesting are those who were on the fence, waiting to see who got the upper hand before deciding which side to join.